The origin of the name “Lemuel” is in the Book of Proverbs, which is attributed to king Solomon. Rabbinic tradition identifies king Solomon with King Lemuel, who is mentioned in the first verse of chapter 31: “The words of king Lemuel, the prophecy that his mother taught him, etc.” In that chapter, king Lemuel is described as sometimes acting foolishly.
Mary was already in love with king Solomon, having read his erotic Song of Songs, and this could explain her naïve enthusiasm towards marrying Lemuel Gulliver.
Come to think of it: It’s remarkable how often parents give their children names, which turn out to be an uncanny description of their character. One might ask which is the cause and which is the effect. “Lemuel Gulliver” is one such example.
The surname “Gulliver” has Old French origin. The French word "goulafre" means “glutton.” Variants of this surname are Gulliford and Galliford, and are first recorded in the Domesday Book of 1086 [yes, 'Domesday' is the correct spelling. If you don’t believe me, Google it!]
Some scholars, mistakenly assuming that Gulliver is a fictitious character, thought that the author - again, mistakenly identified as Jonathan Swift - chose the name Gulliver because it sounded like Gullible. Now that we have the proof that Lemuel Gulliver did exist, we can sneer at those far-fetched assumptions.